Imaging instruments, such as ultrasound probes, have revolutionized the manner in which many important medical procedures are performed. These medical instruments utilize substantially non-invasive imaging techniques to explore and assess the condition of human tissue. As a result of these non-invasive imaging techniques, diagnostic and therapeutic protocols have been developed that allow many highly successful and safe procedures to be performed with a minimum of disturbance to patients.
Ultrasound and other imaging techniques have received widespread acceptance as useful diagnostic tools. An ultrasound image, for example, is created by emission of very high frequency sound waves from a transducer scanning the subject area. The sound waves are reflected back to the transducer, and corresponding data is transmitted to a processing device. The processing device analyzes the data and composes a picture for display on a monitoring screen. Ultrasound probes, and other imaging instruments, may be used in this manner for a variety of purposes, such as identifying the existence, location, and size of tumors, as well as the existence of other medical conditions, including the atrophy or hypertrophy of bodily organs.
It is often desirable to use imaging techniques to guide a needle into a patient. For example, needles can be guided into a tumor to collect a biopsy sample, or can be guided into a location to administer a therapeutic agent. Unfortunately, one significant challenge associated with imaging analysis is that it can be difficult to precisely direct a needle to a target identified during the imaging analysis. Fortunately, a number of quality needle guides have been developed to help direct a needle into a patient. Although these needle guides are useful, they generally do not allow for the precise placement of a needle at shallow angles into targets near the surface of the patient. Therefore, a need exits for an improved needle guide that will allow the placement of a needle into a target that is close to the surface of a patient.